PCV Valve Replacement Interval?

I've been wondering what the interval was on replacing PCV valves in our Toyota's?

Seaching online, it seems to be anywhere from every 20,000 miles to 50,000 miles.

They only cost around $8 and I've only seen one Toyota model (so far) that's more involved to replace (you have to remove the exhaust manifold on one model I looked at.) Else it's just unscrew and replace.

How often do y'all replace yours? (I plan on only using Toyota OEM, of course.)